But AMC already has a new showrunner lined up: Scott Gimple, the supervising producer and writer who has been with "Walking Dead" since early in its second season.

The Hollywood Reporter has the news, saying that Gimple will start his work as showrunner once production on season four begins later in the year. Mazzara will stay with the series until he's finished post-production work on the second half of season three, which has already finished filming.

Gimple has written some of the strongest episodes of "Walking Dead" to date, including the riveting season two eps "Save the Last One" (where Shane's mental breakdown leads him to sacrifice Otis and shave his own head), "Pretty Much Dead Already" (where it's revealed that zombie-Sophia was in the barn the whole time) and "18 Miles Out" (where Rick and Shane nearly kill each other over the fate of their new prisoner Randall). He also wrote the season three episode "Hounded," the first on-screen meeting of Michonne and Rick's prison.

Here's a picture of Gimple. No, he's not the zombie.

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